260Z checking hydraulic fluid???

On a Gravely 260Z mower, my owners manuel is not how clear to me as how to properly check the hydraulic fluid. It just says "unscrew the rod and check fluid" Should it be checked with rod unscrewed and just sitting on fill tube or screwed in and then checked? As this makes almost 1" differance. I wish all mfg would use a standared way. I have 3 mowers, ATV., 3 generators. Some are checked with fill cap just sitting on fill tube others you must screw in in. Sort of hard to remember all of them.